With their own playoff berth now secured following Tuesday’s 105-96 victory over the Rockets, the Nets now have a chance to play a big role in preventing their crosstown rivals from joining them.

When they take the floor against the Knicks at the Garden Wednesday night, the Nets will have a chance to keep them at least two games behind the eighth-place Hawks in the loss column with six games to play, which would make it very difficult for the Knicks — who lose the tie-breaker with Atlanta because of an inferior conference record — to find a way to squeeze into the postseason.

And for Deron Williams — the Nets player with the most time served in the local rivalry — that’s no small thing.

“These games, even if you say they don’t mean more, they mean a lot more,” Williams said. “Just because of the rivalry that’s been formed, and the fans definitely get up for the game, and we do, too. It’s going to be a fun game.”

Williams also admitted the friendly trash-talking that went back-and-forth between the two franchises last summer only added to the growing rivalry between the two teams, which have split the last six games they’ve played.

Still, the two Nets with the most experience in going into the Garden and torturing Knicks fans — Paul Pierce and coach Jason Kidd — downplayed the significance of impacting the Knicks’ playoff hopes.

“We’re worried about our team,” said Pierce, who has a long list of impressive performances in the Garden from his illustrious tenure in Boston. “Truthfully, we’re worried about how far we’re going to go and how far we’re going to rise in the standings. That’s the main thing … the Knicks, they have their own business, but we’re trying to win every game.”

Also sitting out Tuesday were Andrei Kirilenko , who missed his fifth straight game with a sprained ankle, and Marcus Thornton , who sat after aggravating his sore lower back Sunday against the Timberwolves.

“It has nothing to do with it,” Kidd said of the possibility of any added motivation to beat the Knicks. “We have to find a way to win on the road, and they’re fighting for their lives.

“Then, when you mix in the whole Brooklyn-New York thing … it should be fun.”

When he was the general manager of the Timberwolves, Kevin McHale took a chance on a skinny power forward straight out of high school named Kevin Garnett. McHale also sent Garnett to the Celtics in the summer of 2007, a move that helped Garnett and Pierce claim the lone championships of their respective Hall of Fame careers the following season in Boston.

But when McHale was asked before the game if it were strange to see Garnett’s career now winding to a close, he took a philosophical approach.

“No,” he said, “It happens to everybody, bud.

“I’ve been around a long time … I’ve been in the NBA longer than you’ve been alive,” he added, drawing laughter from the assembled media. “I’ve seen many come and go.”

No one has seen Garnett on the court since Feb. 27 in Denver, as Tuesday’s game marked his 17th straight game on the sidelines because of back spasms. The Nets have said he’s targeting a return either this weekend or early next week, when the Nets have a pair of games in Florida against the Heat and Magic.